U.S. patent application number 09/781795 was filed with the patent office on 2001-06-28 for low floor drive unit assembly for an electrically driven vehicle.
Invention is credited to Brill, Lawrence Doyle, Ruppert, Malcolm F., Sullivan, William Carl, Swanson, Glen E..
Application Number | 20010004948 09/781795 |
Document ID | / |
Family ID | 25181361 |
Filed Date | 2001-06-28 |
United States Patent
Application |
20010004948 |
Kind Code |
A1 |
Ruppert, Malcolm F. ; et
al. |
June 28, 2001 |
Low floor drive unit assembly for an electrically driven
vehicle
Abstract
An automotive vehicle drive unit assembly which is located near
the sides of a vehicle includes a first driving axle shaft, a
second driving axle shaft, a first gear box, a second gear box, a
first electric motor, and a second electric motor. The first
driving axle shaft drives a first wheel hub of the vehicle and the
second driving axle shaft drives a second wheel hub. Together the
first and second driving axle shafts define an axis of rotation
about which the first and second wheel hubs rotate. The first gear
set drives the first wheel and the second gear set drives the
second wheel. A first electric motor is mounted in an angular
relationship relative to the axis of rotation and drives the first
gear set. A second electric motor is mounted in an angular
relationship relative to the axis of rotation and drives the second
gear set. A plurality of electric motors can be used to drive each
wheel hub.
Inventors: |
Ruppert, Malcolm F.;
(Hebron, OH) ; Brill, Lawrence Doyle;
(Westerville, OH) ; Sullivan, William Carl;
(Newark, OH) ; Swanson, Glen E.; (Westerville,
OH) |
Correspondence
Address: |
Kerrie A. Laba
Carlson, Gaskey & Olds, P.C.
400 W. Maple Rd., Ste. 350
Birmingham
MI
48009
US
|
Family ID: |
25181361 |
Appl. No.: |
09/781795 |
Filed: |
February 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09781795 |
Feb 12, 2001 |
|
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08801531 |
Feb 18, 1997 |
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Current U.S.
Class: |
180/65.6 |
Current CPC
Class: |
B60K 1/02 20130101; B60K
17/22 20130101; B60K 2007/003 20130101; B60Y 2200/1432 20130101;
B60K 2007/0084 20130101; B60K 2007/0069 20130101; B60K 2007/0076
20130101; B60L 2200/18 20130101; B60K 2007/0038 20130101; B60L
2220/50 20130101; Y02T 10/64 20130101; B60K 17/043 20130101; Y02T
10/645 20130101; Y02T 10/641 20130101; B60L 2220/42 20130101; B60K
7/0007 20130101; B60L 15/007 20130101; Y02T 10/646 20130101; B60K
17/046 20130101; B60L 2220/46 20130101 |
Class at
Publication: |
180/65.6 |
International
Class: |
B60K 001/00 |
Claims
We claim:
1. An automotive vehicle drive unit assembly comprising: a first
driving axle shaft; a second driving axle shaft, said first and
second driving axle shafts being co-linear and defining an axis of
rotation; a first wheel hub driven by said first driving axle
shaft; a second wheel hub driven by said second driving axle shaft,
said first and second wheel hubs driven about said axis of
rotation; a first gear set for driving said first wheel hub; a
second gear set for driving said second wheel hub; said assembly
characterized by a first electric motor mounted at a non-parallel
angle relative to said axis of rotation of said first driving axle
shaft for driving said first gear set, and a second electric motor
mounted at a non-parallel angle relative to said axis of rotation
of said second driving axle shaft for driving said second gear
set.
2. An assembly as set forth in claim 1 including a third electric
motor in parallel driving relationship with said first electric
motor to drive said first gear set, and a fourth electric motor in
parallel driving relationship with said second electric motor to
drive said second gear set.
3. An assembly as set forth in claim 2 wherein said first and said
third electric motors extend radially from said first gear set, and
said second and said fourth electric motors extend radially from
said second gear set.
4. An assembly as set forth in claim 1 wherein a first and a second
gear box houses said first and second gear sets and are rigidly
connected to said first and second electric motors.
5. An assembly as set forth in claim 4 wherein said first gearbox
is fixed relative to said first wheel hub, and said second gearbox
is fixed relative to said second wheel hub.
6. An assembly as set forth in claim 5 wherein said first and
second gear sets include a beveled pinion gear and a beveled ring
gear.
7. An assembly as set forth in claim 1, wherein said first electric
motor is mounted on said first gear box, and said second electric
motor is mounted on said second gearbox.
8. An assembly as set forth in claim 1, wherein said planetary gear
sets are driven by said first and second gear sets resulting in
gear reduction.
9. An assembly as set forth in claim 8, wherein said planetary gear
sets are incorporated into said wheel hubs.
10. An assembly as recited in claim 8, wherein said planetary gear
sets are incorporated into said gearboxes.
11. An assembly as set forth in claim 1 wherein said non-parallel
angle is a 90 degree angle.
12. An assembly as set forth in claim 11 wherein said first and
second gear sets include a bevel pinion gear and a bevel ring
gear.
13. An assembly as set forth in claim 11 wherein said first and
second motors are mounted at a 90 degree angle extending generally
vertically upwardly from said axis of said first and second wheel
hubs.
14. An assembly as recited in claim 12 wherein said first and
second motors are mounted an at axis extending generally
horizontally relative to said axis of said first and second wheel
hubs.
15. An assembly as recited in claim 14, wherein one of said
electric motors is mounted at a 90 degree angle extending generally
horizontally and forwardly relative to said axis of said first
wheel hub and the other said electric motor is mounted at a 90
degree angle extending generally horizontally and rearwardly
relative to said axis of said second wheel hub.
16. A drive unit assembly for a vehicle comprising: a first driving
axle shaft; a second driving axle shaft, said first and second
driving axle shafts being co-linear and defining an axis of
rotation; a first wheel hub to be driven by said first driving axle
shaft; a second wheel hub driven by said second driving axle shaft,
said first and second wheel hubs driven about said axis of
rotation; a first gear set for driving said first wheel hub, said
first gear set including a bevel pinion gear and a bevel ring gear,
with one of said bevel pinion and said bevel ring gear operatively
connected to drive said first wheel hub; a second gear set for
driving said second wheel hub, said second gear set including a
bevel pinion gear and a bevel ring gear with one of said bevel
pinion and said bevel ring gear being operatively connected to
drive said second wheel hub; and a first electric motor mounted at
an angle relative to said axis of rotation of said first driving
axle shaft for driving the other of said bevel pinion gear and said
bevel ring gear of said first gear set, and a second electric motor
mounted at an angle relative to said axis of rotation of said
second driving axle shaft, and operatively connected to drive the
other of said bevel pinon gear and said ring gear.
17. A drive as recited in claim 16, wherein a third electric motor
is mounted in parallel driving relationship with said first
electric motor to assist in driving said first gear set, and a
fourth electric motor is mounted in parallel driving relationship
with said second electric motor to assist in driving said second
gear set.
18. A drive as recited in claim 16, wherein said first and second
motors are mounted at a 90 degree angle extending generally
vertically upwardly from said axis of said first and second wheel
hubs.
19. A drive as recited in claim 16, wherein said first and second
motors are mounted at an axis extending generally horizontally
relative to said axis of said first and second wheel hubs.
20. A vehicle comprising: a vehicle body extending between lateral
sides, passenger seats being mounted adjacent each of said lateral
sides, a floor defined beneath said passenger seats, an aisle
defined between said passenger seats, and said floor also extending
beneath said aisle at least one driving axle for driving a pair of
laterally spaced wheels including a first drive axle shaft
associated with the first of said wheels, and a second drive axle
shaft associated with the second of said wheels; a first and second
gear set for driving said first and second wheels, said first and
second gear set each including a bevel pinion gear and a bevel ring
gear, with one of said bevel pinion gear and said bevel ring gear
operatively connected to drive each of said first and second
wheels; a first electric motor mounted at a non-parallel angle
relative to said axis of rotation of said first driving axle for
driving the other of said pinion gear and said ring gear of said
first gear set, and a second electric motor mounted at a
non-parallel angle relative to said axis of rotation of said second
driving axle and operatively connected to drive the other of said
bevel pinion gear and said ring set; and said electric motors being
mounted at a vertical position which is higher than a vertical
position of the floor of said aisle.
21. A vehicle as recited in claim 20, wherein bevel pinion gears
and bevel ring gears are utilized to transmit rotation from said
first and second electric motors to said first and second
wheels.
22. A vehicle as recited in claim 20, wherein said non-parallel
angle is a perpendicular angle.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to a unique drive arrangement for
electrically driving the wheels of a vehicle in such a way that the
floor of the vehicle may be lower than was the case in the prior
art.
[0002] Mass transit vehicles, such as a bus or trolley car,
typically have seats aligned at the lateral sides of the vehicle,
with a central aisle extending along the vehicle. The seats are
typically at a higher vertical location than the aisle, and thus
cover the wheels. It would be desirable to have the aisle
positioned relatively low to the ground. This would provide
increased passenger space within the body of the vehicle, and may
allow the designer to reduce the overall height of the mass transit
vehicle. Other advantages to having a lower floor position include
improved handicapped access and greater ease in the loading and
unloading of passengers.
[0003] Mass transit vehicles typically have several axles which
support and drive or steer the vehicle. If the axle is a driving
axle, then electric motors can be used to generate torque to drive
the wheels. In a typical configuration, a centrally located
electric motor drives two opposed wheels at the sides of the
vehicle by way of a conventional axle. Usually, transmissions or
drive shafts extend from the central motor to the axle.
[0004] In the prior art, there are relatively large motor,
transmission, or axle elements directly below the center of the
vehicle. The aisle is typically in the center of the vehicle and
normally goes over the axle, thus requiring the floor of the aisle
to be relatively high. One known bus moves the floor up by steps
over the axle. It is undesirable, however, to have passengers climb
steps to reach the aisle and seating areas.
SUMMARY OF THE INVENTION
[0005] The subject invention relates to an automotive vehicle drive
unit assembly which includes a first driving axle and a second
driving axle which together define an axis of rotation. The drive
unit assembly further includes a first wheel hub and a second wheel
hub which are driven about the axis of rotation. A first gear set
drives the first wheel hub and a second gear set drives the second
wheel hub. A first electric motor is mounted at an angle relative
to the axis of rotation of the first driving axle and drives the
first gear set, and a second electric motor is mounted at an angle
relative to the axis of rotation of the second driving axle and
drives the second gear set.
[0006] This invention improves packaging and increases passenger
compartment size by moving the electric motors to the sides of the
vehicle. This allows the interior vehicle floor to be lowered
between the motors resulting in improved utilization of the
passenger compartment. Also, the flexibility of mounting the
electric motors at various angles with respect to the axis of
rotation of the first and second driving axles results in flexible
packaging designs for other vehicle components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Other advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0008] FIG. 1 is a cross sectional view of a vehicle incorporating
the subject invention;
[0009] FIG. 2A is a cross sectional view taken along line 2-2 of
FIG. 1, showing a first electric motor arrangement;
[0010] FIG. 2B is a view like FIG. 2A, but showing an alternative
electric motor arrangement;
[0011] FIG. 3 is a fragmentary view from the inside of the left
wheel hub as shown in FIG. 2, partially broken away and in cross
section, and showing a first embodiment of an electric motor
arrangement;
[0012] FIG. 4 is a cross section view from the front of the left
wheel as shown in FIG. 3, and showing the first embodiment of an
electric motor mounting arrangement;
[0013] FIG. 5 is a view like FIG. 3 but showing an alternative
electric motor mounting arrangement; and
[0014] FIG. 6 is a view like FIG. 4 but showing the alternative
electric motor mounting arrangement.
[0015] FIG. 7 is a view like FIG. 3 but showing an additional
electric motor.
[0016] FIG. 8 is a cross sectional view of a gear box showing an
alternative embodiment incorporating a planetary gear set.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0017] Referring to the Figures, wherein like numerals indicate
like or corresponding parts throughout the several views, an
automotive vehicle is shown generally at 10. As shown in FIG. 1,
automotive vehicle 10 includes a passenger compartment 12 defined
by a roof 14, two side walls 16, and a vehicle floor 18. A pair of
wheels 19, 21 are driven by an automotive vehicle drive unit
assembly, generally shown at 20, which has a first unit 22 and a
second unit 23. It should be understood that vehicle 10 is
typically provided with a pair of drive units and several pairs of
wheels.
[0018] As shown in FIG. 2A, the first unit and second units 22 and
23 define an axis of rotation 26. As shown in FIG. 3, a first
driving axle shaft 24 drives a first wheel hub 28 which revolves
about the axis 26 of the first driving axle shaft 24.
[0019] A first gear set 30, located adjacent to the first wheel 19,
is comprised of a pinion gear 32 and a ring gear 34 which together
drive the first wheel hub 28. A first electric motor 36, defining a
motor axis of rotation 38, is mounted at a non-parallel angle
relative to the axis of rotation 26 of the first driving axle shaft
24. The first electric motor 36 is shown mounted in a horizontal
position such that the motor axis of rotation 38 is parallel to the
vehicle floor 18 and is perpendicular to the axis of rotation 26 of
the first driving axle shaft 24.
[0020] As shown in FIG. 2A, drive unit assembly 20 further includes
a second unit 23 comprising a second driving axle shaft 24, a
second wheel hub 28, a second gear set 30, and a second electric
motor 36. It is understood that the second unit 23 is a mirror
image of the first unit 22. A beam 58 provides a fixed housing
extending between the first 22 and second 23 units.
[0021] The first 36 and second 36 electric motors can be mounted in
various different positions relative to each other. As shown in
FIG. 2A, the first 36 and second 36 electric motors can be mounted
in a generally horizontal position with both electric motors 36
extending forwardly from the beam 58. Where packaging would allow,
the electric motors 36 can also be mounted such that they both
extend rearwardly from the beam 58. As shown in FIG. 2B, the first
36 and second 36 electric motors can be mounted in a generally
horizontal position with the first electric motor 36 extending in a
forwardly direction relative to beam 58 while the second electric
motor 36 extends in a rearwardly direction relative to beam 58.
Arranging the configuration so that one electric motor 36 extends
forwardly while the other electric motor 36 extends rearwardly can
resolve electric motor weight balance issues that arise when both
motors extend in the same direction from the beam 58.
[0022] As can be seen in FIG. 3 and 4, a first gear box 40 houses
the first gear set 30 and is rigidly connected to the first
electric motor 36. A motor drive shaft 42 extends from the electric
motor 36, along the motor axis of rotation 38, and drives the
pinion gear 32. The pinion gear 32 meshes with the ring gear 34
which revolves about the axis 26 of the driving axle shaft 24. As
the ring gear rotates, it drives the driving axle shaft 24 which
turns the wheel hub 28. As can be seen in FIG. 4, gear box 40 is
fixed to beam 58.
[0023] A planetary gear set, shown generally at 46 in FIG. 4, can
be used to achieve greater overall gear reduction. The planetary
gear set 46 can either be located adjacent to the wheel hub 28 or
can be incorporated into the gear box 40. The planetary gear set 46
shown in FIG. 4 is located adjacent to the first wheel hub 28 and
is driven by the first driving axle shaft 24. The planetary gear
set 46 shown in FIG. 8 is incorporated into the gear box 40.
Regardless of its location, the planetary gear set 46 includes a
sun gear 48, planet gears 50, and a ring gear hub 52. Each planet
gear 50 is attached to a single planetary spider 53 by a
corresponding planet pin 51, thus forming a planet gear assembly,
as shown in the enlarged view of the planetary gear set 46 in FIG.
8. The planet gear assembly is inserted into the ring gear hub 52
such that the teeth of the planet gears 50 mesh with the teeth of
the ring gear hub 52.
[0024] In a typical configuration there are three planet gears 50
in a planet gear assembly but it is understood that a different
number of planet gears 50 can be used. When the planetary gear set
46 is located adjacent to the wheel hub 28, as shown in FIG. 4, the
sun gear 48 is attached to and driven by the first driving axle
shaft 24. As the sun gear 48 rotates, it meshes simultaneously with
each of the planet gears 50 in the planet gear assembly. The planet
gears 50 mesh with the ring gear hub 52 which results in the
turning of the first wheel hub 28. The entire planetary gear set 46
is housed within a planetary hub 54 located adjacent to the first
wheel hub 28. It is understood that the drive unit assembly 20 does
not require a planetary gear set 46 for operation. The planetary
gear set 46 is an optional feature of the drive unit assembly
20.
[0025] As shown in FIG. 8, the planetary gear set 46 can also be
incorporated into the gear box 40 instead of being located adjacent
to the wheel hub 28. Incorporating the planetary gear set 46 into
the gear box 40 is a unique location for the planetary gear set 46.
Typically, this location has been used by a differential which
includes a ring gear and a pinion gear which drive axle shafts
which in turn drive the wheels. With independent electric motors 36
there is no need for a differential or for any direct mechanical
link between opposing wheels. By incorporating the planetary gear
set 46 into the gear box 40, the need for a planetary hub 54 is
eliminated which decreases the vehicle weight, gives a broader
selection of wheel equipment and wheel end features, and reduces
overall cost.
[0026] FIG. 5 and 6 show an alternate embodiment of the mounting
arrangement for the first electric motor 36. The first electric
motor 36 is shown mounted in a vertical position such that the
motor axis of rotation 38 is perpendicular to the vehicle floor 18
and is perpendicular to the axis of rotation 26 of the first
driving axle shaft 24. In a typical configuration, the first
electric motor 36 is mounted either in a horizontal or vertical
position. However, the electric motor 36 can be mounted at any
angle with respect to the vehicle floor 18 and the axis of rotation
26 of the first driving axle shaft 24.
[0027] FIG. 7 shows an alternate embodiment of the drive unit
assembly 20 in which the first unit 22 includes a third electric
motor 56, in parallel driving relationship with the first electric
motor 36. The third electric motor 56 is also used to drive the
first gear set 30. The second unit 23 is a mirror image of the
first unit 22 and includes a fourth electric motor 56, in parallel
driving relationship with the second electric motor 36. The fourth
electric motor 56 is use to drive the second gear set 30. The use
of a third 56 and fourth electric motor 56, where packaging space
is available, allows smaller gears and motors to be used, thus
reducing the necessary size for the system.
[0028] With the present invention, the benefits as shown in
particular in FIG. 1 are achieved. By mounting the motors at the
sides of the vehicle, the center of the vehicle floor may be
lowered significantly than compared to the prior art. In addition,
since the motors themselves are connected to drive the wheels to a
non-parallel angle, they do not extend towards the center of the
vehicle from the wheel for any undue amount. Thus, the lower floor
can begin at a laterally outer position. If the motors extended on
an axis parallel to the axis of the wheel, the motor would require
a higher floor for more of the lateral width of the vehicle.
[0029] The invention has been described in an illustrative manner,
and it is to be understood that the terminology which has been used
is intended to be in the nature of words of description rather than
of limitation.
[0030] Another method of mounting the motors for the present
invention is disclosed in co-pending patent application Ser. No.
______ entitled "Suspension Drive Unit Assembly for An Electrically
Driven Vehicle". Another mounting of the motor relative to the axle
of the wheel hub is disclosed in co-pending patent application Ser.
No. ______ entitled "Space Saving Connection for Electric Drive
Motor to Wheel Hub".
[0031] The invention has been described in an illustrative manner,
and it is to be understood that the terminology which has been used
is intended to be in the nature of words of description rather than
of limitation.
[0032] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is,
therefore, to be understood that within the scope of the appended
claims, wherein reference numerals are merely for convenience and
are not to be in any way limiting, the invention may be practiced
otherwise than as specifically described.
* * * * *